Improved steam slide-valve



MONROE STANNARD, 0F HARTFORRUONNECTICUT.

Letters Patent N 97,456, dated .November 30, 1869.

IMPROVED STEAM SLIDE-VALVE.

i The Schedule referred to in these Letters Patent and making part of the'same.

To all whom it may concern Be it known that I, MONROE S'ralvivauo, of the city and county of Hartford, in the State of Connecticut, have invented certain new auduset'ul lmprovements in Slide-Valves; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to theaccompanying drawings, and to the letters of` reference marked thereon.

My invention relates to slide-valves for steam-engines or hydraulic-apparatus, and has for its object to produce a practicable arrangement whereby thepower required to move the valve may be lessened.

I may here mention, that 1 am aware that, prior to my invention, an arrangement has been used in which the valve itself rides on anti-friction rolls, so adjusted as to prevent absolute contact of the valve with its seat. 'lhe adjustment of the valve face relatively to the rolls audits sc at, is always att-ended with great difficulty, and the arrangement is not well adapted to varying pressures of steam, nor does it afford means ot compensating for wear lot' the parts.

I am also aware that valves have been balanced by connecting with them a cyliudcr,'iu which fits a! piston, which has been suspended o1' supported by a vibratory link, whereby a portion or the whole of the pressure, which would have forced the valve upon its seat, is transferred to the piston, and to the pivots of its sustaining-link. This arrangement is not couvenient of application, and involves obiectionable wear of the cylinder and piston, caused by their constant rolative movements.

My invention consists in so combining anti-friction wheels or rolls with av partly or perfectly-balauced valve, that the part of' the balancing-apparatns, to

p which the pressure is transferred, may be supported by and ride on the said rolls or wheels, while, at all times, the valve may be free to find its seat, and adjust itself vertically thereto.

'lo enable others skilled in theart to make and use my invention, I will proceed to a description of sonic of' its practical applications.

Figure 1 shows a central longitudinal vert-ical section of a locomotive steam-chest and valve, embodying my invention; I

Figure 2 shows a view Yof" the interior of the chest, its side being removed to show a side view of' the valve;

Figure 3 isa central cross-section ofthe apparatus; and

Figure 4, a plan of thc saine, drawn on a reduced scale.

To these four ligures 'the immediately fbllowing part of the description particularly refers.

a indicates the valve-seat, and b, the valve, which has in it an exhaust-cavity, c, and operates to admit and release steam-to and from both ends ofthe cylinder in the same way as any sin-- glo eup slide-valve.

To the top ofthe valve is attached a tubular piston, rt, the interior of' which con'nnunicates with the exlniust-cavity c.

" The piston d enters and fits steam-tight in a short C linder, e, which is closed at its upper end, and near.

its lower end is furnished with an external flange, j, of rectangular form. valve face, and projects laterally beyond the ends of the valve, where it supported, at each end, upon series of anti-friction rolls g, which rest on tracks parallel with the valve-seat.

The rolls g are kept in their proper relative positions ,by pins passing through their axes, and fixed to parallel bars h, located one on each side of' each series.

7n is the valve-rod, by which the valve and conseqnentlythe cylinder with which it is connected are moved.

It will be readily nnderstomi, by those who are familial' with the principles of balanced valves, that part. or the whole of' the downward pressure, which would otherwise have been exerted upon the valve, is, by the described arrangement, prevented from acting on the valve, and is trai'if'erred to the cylinder, which, as it is supportedion, and rides 1o?! the anti-friction rolls y, may be easily moved even under great pressure. The proportion ot' weight tlmsprevented from pressing on the valve may, by properly proportioning the area of the cylinder, be so regulatedV that thc valve will be pressed down with only sufficientforec to keep it in contact with it-s scat, and thereby its friction and wear may be reduced to aminimum- The valve, by reason of its connection through the piston with the cylinlder, is free to move vertically, and is thus rendered self-adjusting relatively toits seat. This makes the adjnstn'lent of' the size of' the rolls 1or and thc height oi' the track on which they roll, a matter of little importance. lhcre will be little or no wear of' the piston and cylinder, because their relative movements only take place'by the imperccptibly slow change caused by difference of' wear ot' the vz'llve-seat and face and the rolls and tracks. u

Although the piston (l may be furnished with any suitable kind ot' packing, which will make it steamtight in the cylinder, yet I. will describe the one I deem best, the peculiar.fiatnres ot' which are of my invention.

`ihe piston d is flanged at top and bottom, which makes a recess in its` periphery.` The upper part of' this recessie lled with hemp, India rubber, or other suitable elastic material, (indica-ted by m in figs. l and This flange is parallel with the 3,) while the lower' part ot the said recess is occupied by ametal ring, n, which is bevelled at its upper edge.

One or more holes, o, are drilled throughthe lower' flange, and these communicate with an annular groove or channel, 1;,just under the ring nf. This channel forms a steam-space under the ring n, into which space steam passes through the holes o, and forces the ring n upward against the elastic packing m, which is thereby compressed and forced against the bore of the cylinder. A seliadjusting packing is thus furnished, which seldom requires attention.

The ring a is made in two parts, one of which is shown in plan by Figure 5, but the second ring could be in one piece, if either tiange of the piston l1 were made removable.

Figures 6 and 7 illustrate another modification of my invention, as applied to a simple slide admissionvalve without an exhaust-cavity.

a is the valve-seat;

b, the valve; and

c, the steam-port.

d is a cylinder, formed on the valve, and

e, a piston fitting therein.

This piston is attached to a yoke, e', the ends of which rest on the anti-friction rolls g.

This plan involves no principle different from the one first described, and needs no further explanation,

exceptthat any steam or water which may leak into the cylinder cl will discharge itself through a small hole, p, which passes downward through the valve, and is so located that it will communicate iwith the port c, when this is covered by the valve, but will be closed by lying over the seat when the port is open.

Othereqnivalent parts may be substituted, with,- out departing from the` substance of my invent-ion, as an example of which, I may mention that aiiexi- 'ble diaphragm attached tothe valve and to a. plate supported on rolls or wheels, may be substituted for the pist-on and cylinder hereiubeiore described.

\Vhat I claim as my invention, and wish to secure by Letters Patent, is-

1. The combination, with the described balancevalve, of anti-friction rolls, substantially' as hereinbefore set forth.

2. The combination of the ring 01,'the steam-cow' munications o, and the yielding packing m, with the piston il and cylinder' e of a. balance-valve, substantially as above specilied.

In testimony whereof. I have hereunto set my hand, this 27th day of May, 1867.

MONROE STANNARD. Witnesses:

Unas. Ii'. OWEN, Unas. J. COLE. 

